Arbitrary file upload in 23andme Yamale

CVE-2021-38305

23andMe Yamale before 3.0.8 allows remote attackers to execute arbitrary code via a crafted schema file. The schema parser uses eval as part of its processing, and tries to protect from malicious expressions by limiting the builtins that are passed to the eval. When processing the schema, each line is run through Python's eval function to make the validator available. A well-constructed string within the schema rules can execute system commands; thus, by exploiting the vulnerability, an attacker can run arbitrary code on the image that invokes Yamale.

Vulnerability class: Unrestricted File Upload

EPSS: 0.025 (83.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

  • cve@mitre.org (Third Party Advisory, x_refsource_MISC, Release Notes)
  • cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2021-38305?
CVE-2021-38305 is a high-severity vulnerability in 23andme Yamale, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 7.8/10. Published 2021-08-09.
How severe is CVE-2021-38305?
High severity. CVSS v3 base score is 7.8 out of 10.